Space heater



July 30, 1946. D. M. TRiLLlNG ETAL SPACE HEATER 5 Sheets-Sheet l Filed Deo. 7, 1944 Jui? 30, 1946- D. MJTRlLLnlG ETAL- 2,405,072

SPACE HEATER w www' Dpwlv mlTEvLLnNG GEofaGe H-RiC-Hv Juy 30, 1946.

D. M. TRILLING ET AL SPACE HEATER Filed Dec. '7, 1944 www m. TRM LIN@ 1- GEORGE H MCH Patented July 30, 1946 SPACE HEATER David M. Trilling, Merion, and George H. Rich.,

Philadelphia, Pa., assignors to David M. Trilling, Merion, and Harry Montague, Philadelphia, Pa., a partnership Application December 7, 1944, Serial No. 567,032

4 Claims.

This invention relates generally to space heaters and more particularly to an improved construction of cabinet type heater which is so designed and constructed as to provide for maximum utilization and distribution of the heat derived from a primary source.

Among the principal and important objects of the present invention is to provide a space heater which is so internally provided with a plurality of nues in communication with each other and with atmosphere as to prevent the entrapment of heated air within the interior of the cabinet to such extent that it might build up to a dangerous degree of temperature, the filles within the cabinet being so arranged in relation to each other as to insure the release of heated air from within the interior of the cabinet during all possible conditions of use of the cabinet.

A further important object of the present invention is to provide a space heater which is internally provided with several flue-forming elements so arranged in relation to each other and to surrounding parts of the heating cabinet that all said parts mutually reenforce each other to provide a. rigid and rugged construction of cabinet heater at the same time that they provide the cabinet with iiues which serve not only to most eiiiciently direct the heated air outwardly of the heater cabinet, but also to maintain the external side surfaces thereof relatively cool.

A further object of the present invention is to provide a cabinet heater which is designed to create a self-activated movement of the heated air through the heater cabinet and so insure positive circulation and distribution of the heated air without necessitating the employment of auxiliary air circulating devices, such as a fan- Still another object of the present invention is to provide a cabinet construction of space heater which is exceedingly simple and pleasing in design, rugged and durable in construction, economical of manufacture, and eiicient and safe in use.

Other objects and advantages of the present invention will appear more fully hereinafter, it being understood that the present invention consists substantially in the combination, construction, location and relative arrangement of parts,

al1 as described in more or less detail hereinafter,

as shown in the accompanying drawings, and as nally pointed out in the appended claims.

In the said accompanying drawings, which are illustrative of certain preferred constructions embodying the principles of the present invention:

Figure 1 is a. perspective view of a cabinet heater constructed in accordance with and embodying the principles of the present invention;

Figure 2 is a vertical sectional view taken on the line 2--2 of Figure 1;

Figure 3 is a horizontal sectional view taken on the line 3 3 of Figure 2; Y Y

Figure 4 is a perspective view of the internal flue-forming unit, one panel thereof being broken away to show the heating elements supported by said unit;

Figure 5 is a Vertical sectional view taken on the line 5-5 of Figure 4;

Figure 6 is a detail view showing a preferred method of securing the support for the heating element within the internal flue-forming unit;

Figure 7 is a partial sectional View further illustrating the constructional detail of Figure 6 as taken along the line 'l-l of Figure 6;

Figure 8 is an elevational view of the lowerportion of one end of the external cabinet showing the means for removably supporting in position the bottom panel of the heater cabinet;

Figure 9 is a sectional view taken on the line 9-9 of Figure 8;

Figure l0 is a perspective View similar to Figure 4 showing a somewhat modified construction of the internal flue-forming unit;

Figure 11 is a longitudinal sectional view of the cabinet heater of the present invention as taken along'the line II-II of Figure 1 employing the modified internal unit of Figure 10J said Figure ll being taken substantially on the line II-II of Figure l; and

Figure 12 is a horizontal sectional view taken 0n the line IZ-I 2 of Figure l1.

Referring now to the drawings and more particularly to Figures 1, 2, 3 and 4, it will be observed that the space heater of the present invention essentially consists of an external cabinet or housing designated generally by the reference numeral I0, an interna1 Hue-forming unit designated generally by the reference numeral II, and one or more primary sources of heat, preferably in the form of coiled electrical resistance elements designated generally by the reference numeral I2.

The cabinet I0 is formed throughout of suitably perforated sheet metal panels suitably secured together, preferably by Welding, to provide the cabinet With a perforated top panel I3, perforated end panels I4-I4, and perforated side panels I5I5. The cabinet is provided with vertically extending corner posts I6, each of which is of generally right-angular cross-section, the flanges of which overlap and are spot welded to the vertical edges of the side and end panels of the cabinet. These corner posts serve not only to rigidify the external cabinet, but also as the supporting legs therefor. The top panel i3 of the cabinet is fitted within a marginal frame E7 which in turn snugly ts over and is welded to the upper edges of the side and end walls of the cabinet. As most clearly appears in Figures l and 2, these side and end walls of the cabinet terminate a substantial distance above the floor line of the cabinet so as to provide for adequate circulation of air from the surrounding atmosphere into the interior of the cabinet by way of the bottom thereof.

Removably secured within the cabinet is a bottom panel i8 which is also formed of perforated sheet metal, this bottom panel i3 beingl provid-edalong its opposite longitudinal edges with downwardly turned iianges lS-IQ to rigidity the same. In order to support this bottom panel i in position within the cabinet, the opposite side walls i5-l5 thereof are each provided with a pair of longitudinally extending angle members E9-29 respectively spot welded to the inner faces of said side panels, the freely extending flanges of these angle members Ztl-29 serving as stops or seats against which the bottom panel i8 may be upwardly pressed (see Figure 2), the said bottom panel I8 being held against the members 2& 29 vby a plurality of bendable clips 2l respectively secured to each of the end panels tit-lll in the 'immediate region of each corner of the cabinet.

These clips 2i are shown most clearly in Figures 2, 8 and 9 and consist simply of metal tabs each folded upon itself to provide a portion 22 which is welded to the end panel and a freely extending tab 23 which is adapted to bebent out of the full line position sho-wn in Figure 9 into the dotted line position shown therein. In securing the botto-m panel i8 in place within the cabinet lil, the tab portions 23 of the supporting clips 2| are initially bent or pressed into their full line position, as shown in Figure 9, to thereby permit the bottom panel I3 to be freely seated against the longitudinally extending stops or seats 29, the tabs 23 being thereupon bent or sprung into the dotted line position shown in Figure 9 to engage the lower surface of the bottom panel i8 in the region of each corner thereof to hold the panel against the said longitudinally extending stops or seats Ztl-2li. In order to remove the bottom panel, should it be necessary to do so for servicing the heater, it is only necessary to spring the tabs 23 back into their initial full line position shown in Figure 9, thereby permitting the bottom panel to be freely slipped out of its` retained position.

The flue-forming unit il (see particularly Figures 4 and 5) is disposed internally of the cabinet and is supported therein as shown in Figures 2 and 3 by means of the bottom panel it. This internal flue-OImiIlg unit is essentially formed of a plurality of sheet metal panels secured together to provide a hollow unit having the side walls 24-24 and the end Walls 25-25. The end panels i5-25 of this hollow unit are each formed along their vertical edges with diverging winglike flanges 26, the vertical edges of which are respectively adapted to more or less snugly nt within the interior vertical corners of the external cabinet I. These wing-like flanges 25 of the inner unit thus serve to center the said unit within the external housing or cabinet iti, as is shown most clearly lin Figure 3, the uppermost edges of the internal unit being in engagement with the top panel I9 of the cabinet Il), while the lowermost edges of said internal unit rest upon the bottom panel i8 of the external cabinet. Thus, the internal unit Il is secured against all possibility of movement within the external cabinet, yet it may be readily removed therefrom, should that be necessary, by the simple expedient of removing the bottom panel i8v of the main cabinet.

It will be noted that when the internal unit is properly positioned within the external cabinet,

Gil

it forms in conjunction therewith a plurality of air ducts or-ilues which are freely open to atmosphere' at theY topand bottom ends of each. The

internal' unit' ii, being of hollow form, in itself constitutes a main central flue within which are disposed the primary heating elements i2. The auxiliary side lues are respectively formed between each of the side panels 2li- 2li of the central unit and the side panels IE5- i5 of the external cabinet, and between each of the end panels z5-25 of the central unit and theendV panels iii-ifi of the external cabinet. Thus, the main central flue of the space heater of the presentl invention is surrounded upon each of its four sides by an auxiliary flue of substantial propo-rtion.

t will be noted that each of the side panels 'Ed-2d of the central unit are vertically ofi-set with respect to the end panels 25-25 thereof so as to provide in effect a pair of opposed notches of substantial width at the top and bottom of the central unit. One pair of these notches, designated Zl-Zl, is provided at the upper edges of the end panels 2E-25, while the other pair, designated 28, is provided at the bottom side panels 2li-2d. In addition, the end-panels'Z-'l are each notched, as at 29, in their bottom edges, while the panels Zd-Zl are each notched, as at 3c, in their upper edges'. The provision of these notches or spaces in the regions of the opposite edges of the several panels forming the central unit is quite important because they provide for free circulation of heated airi'rom within the central flue of the inner unit outwardly of the cabinet by way of one or more of the surrounding auxiliary air ducts orrlues. y

It has been iound that in the operation of a space heater constructed with the several' communicating ues as just described, a mostl eilie cient circulation and distributionv of heated air into the space surrounding the heater is obtained, all without excessive or undue heating ofl the external Walls of the cabinet. This isundoubtedly due to the provision and design of the several flue passages, all of which cooperate not only to produce a most eirective circulation of heated air through and upwardly out of the` cabinet, but also provide for the circulation or relatively cool air upwardly about all sides ofthe main central line whereby to maintain the sideA externalY suri'aces of the cabinet relatively cool. In this connection, it will be noted that the space which is formed immediately above the upper end of the central flue is in' direct communication with the several flues which surround the main central flue in which is located the primary source of heat. Also, these surrounding ues are each in communication with the surrounding atmosphere by way of the perforations in their side enclosing external panels at the saine time that they are in direct communication by wayl of the notches 2l, 28, 29A and 33 aforesaid withY the interior of the main central flue.

As the heated air rises out of the`- centrallue and thence outwardly through the perforated top I3 of the heater, it tends to draw cool air upwardly through all of the several auxiliary flue passages, and inasmuch as the air which is so drawn upwardly through these outer flues is rel- Yatively cool, there is no danger of overheating the exposed sides of the heater cabinet. Also, by reason of the fact that the cabinet is so provided with the several fiue passages as described, all of which are in direct communication with each other and with the surrounding atmosphere by Way of the perforated top, end and side panels of the cabinet, as well as by way of the perforated bottom panel of thel cabinet, the hazard of heat being built up within the interior of the cabinet to a dangerous degree is entirely eliminated. In this connection, it has been found that when the cabinet is subjected to the severest smothering test, as by blanketing the top and practically all of the perforated side Walls thereof, the heated air developed within the cabinet is free to escape to the surrounding atmosphere by way of some of the uncovered openings in one or the other of the side walls of the cabinet, while if all sides of the cabinet are completely smothered, the air is still free to escape to the surrounding atmosphere by way of the bottom openings of the several flue passages, all of which are in connection with atmosphere by Way of the perforated bottom panel I8 of the cabinet. Consequently, the internal temperature or' the cabinet is at all times maintained at a safe limit. The provision of the several connecting internal nues and the passages in all sides of the cabinet assures an adequate avenue of escape for the heat developed in the cabinet no matter in what position the cabinet may be placed, as for example, should it be inadvertently turned upon one of its sides or ends or even inverted top for bottom. In the foregoing respects, the principles of operation of the space heater of the present invention are the same as those set forth in our copending application Serial No. 528,032, filed March 25, 1944, and to which reference is specifically made herein.

While the space heater of the present invention, including its external cabinet and its internal flue-forming unit, is adapted for use in connection with any suitable source of primary heat, it is preferred to employ as such source of heat one or more electrical resistance units such as the element I2 shown in the drawings. These electrical resistance units are each preferably in the form of a hollow refractory tube 3| (see Figure 7) upon the external surface of which is suitably Wound a coil of resistance wire 32. Preferably, this resistance wire 32 is wound upon the tube in doubled form, the bight end of the loop of wire being suitably secured, as at 32a, within an aperture formed in the Wall of the tube adjacent the upper end thereof. By so doubling the resistance Wire upon itself and then spirally winding the wire about the tube with each convolution oi' the wire retained in its own spiral groove formed in the external surface of the tube, the terminal ends of the resistance coil may be located at the relatively cool bottom end of the refractory tube for respective securement to the terminal pins 33 of the space heater. Where two such resistance units are employed, as illustrated in the drawings, they are connected in series, one terminal end of one coil being connected to another terminal end of the other coil by means of a common electrical connecting element or post 34, which is insulatingly secured to one of the side panels 24 of the internal nue-forming unit I I The remaining ter-f minal extremities of the series connected resistance coils are then respectively connected to the terminal pins V33 which are suitably secured to and insulated from the opposite side panel 24 of the inner unit II.

By virtueof the means employed for mounting the electrical heating elements I2-I2 in position within the inner unit II, undesired pocketing of th heat interiorly of the refractory tube 3I is entirely eliminated, thereby not only prolonging the useful life of the heating element, but also making available for heating purposes the heat which is developed interiorly of the tube. This mounting means is Amost clearly disclosed in Figures 4 to 7, inclusive, wherein it will be observed that each element I2 is supported in vertical position between a pair of vertically spaced oppositely facing cup-like members 35-35. Each of these cup-like members 35 is centrally apertured, as at 36, to provide an opening which is in registry with the bore bf the refractory tube 3|, the supporting members 35-35 for each tube being respectively secured, as by welding or otherwise, to a pair of transversely extending supporting bars 31-31. These bars 31 are of a length sufficient to extend across the full width of the inner nue-forming unit II, the opposite ends of each bar being provided with depending tabs 38 which are adapted to be inserted within suitable sockets 39 therefor provided upon the inner faces 24--24 of the unit II. These socket members 39 are arranged in pairs so vertically spaced from one another that When the tab ends of the supporting bars 31 are inserted therein, each pair of oppositely facing cupped members 35-35 are spaced apart a distance just sufficient to snugly receive therebetween one of the resistance heating units I2. As most clearly appears in Figure 4, the transversely extending supporting bars 31, to which are secured the cupped members 35, are of relatively narrow width as compared with the diameter of the central opening 36 of each member 35 to thereby insure the free passage of heated air upwardly through and out of the bore of the refractory tube 3l. In order to lock the transversely extending bars 31 in position, the depending tabs 38 respectively provided at their outer extremities are formed of sufficient length that when the same are inserted in their sockets 39, the lower ends thereof may be clinched over, as at 40 (see Figure 7), to prevent unintentional or accidental displacement of the bars, should the heater be inadvertently turned upon its side or inverted top for bottom.

Figures 10 and 11 show a modified construction of heater wherein the inner unit is formed of a plurality of panels having co-planar top and bottom edges. The opposite side panels 24e-24a are each provided adjacent the upper and lower edges thereof with a pair of elongated slots or openings 4I-4I, while the end panels 25a-25a are each similarly provided adjacent the top and bottom edges thereof with an elongated slot or opening 42. These slots 4I and 42 serve the same function as the notches or spaces 21, 28, 29 and 33 formed in the inner unit of the construction shown in Figure 4, the space heater of Figures 10 and 11 being in all other material respects similar to that hereinbefore described.

It will be noted that in the cabinet type space heater of the present invention, the coiled resistance heating units are electrically connected to the terminal pins 33 which are mounted in the side panel of the inner unit. These terminal pins f of temperature,

ventiona-l; electric cord set,` and, to. thisV end',l the external cabinet is provided; ignits corresponding sidewall Withanlopening 4-3 through whichaccess.

isprovidedto-the terminal pins- 33. By so mounting the terminal pins upon the sidelpanel of the inner unit, they: are protected against likelihood of damage While at the vsame time the external cabinet is free of any externally projecting elements.

The: cabinet construction .of thetpresent inl/er1- tion, providingras. it; does maximum utilization andA circulation ofk the heated air,A makes it possible to employ low: temperature heating coils. That is tol say;v the electrical resistance elements I2 are so designed that they operate in black rather v than in the, incandescent red heat. range This, of course, is effected by utilizing; resistance wire of such gauge and of such number ofconvolutions as to insure the generation of adequate heat for a given wattage without any incanclescence` of the resistance wire. The multiple-flue cabinet construction of the present invention, in creating a self-activated movement of they heated air through the cabinet,

insures; rapid and positiveI distribution of theheat generated by the heating coils. v

Of course, it will ber understood that the present invention is, susceptible of various changes and modications which may be made from time to time without departing from the general prin clples or real spirit thereof, and accordingly, it is intended to claim the inventionhroadly, as Well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. In a space heater of the character described, in combination, an assembly comprising an openended inner casing, an electrical heating unit disposed Within said casing, said heating unit being of hollow construction to provide a through air passage extending4 vertically therethrough from end to endvparallel to the axis of the casing, and means. for supporting said heating unit within said casing with the opposite ends of said unit 8 open to the flow of air therethrough from and to theH atmosphere;i and. any outer casing having its side, top-and bottom walls perforated over a major portion thereof, said assembly being disposed within and supported by said outer casing to form main inner and auxiliary outer air stream lues,

all of which latten as well as the air passage through said heating, unit, being freely open to atmosphere by Way of their opposite ends and being arranged t@ provide a plurality of parallel passages for the, unidirectional ow of air upwardly through the space heater.

2. In. a space heater of the character deiined in claim 14 wherein said top and bottom Walls of the;A outer casingserve conjointly to supportsaid inner casing against vertical displacement within said outer casingL said bottom Wall of the Vouter casingY being removable therefrom to afford acf cessv to; said assembly disposed within` said outer casing- 3.K In a space heater of the character defined in claim l wherein said inner casingA is provided with perimetrally spaced externally projecting wing-like elements the free edges of Whichengage the embracing walls of the outer casing to maintain said inner and outer casings in spaced relation.

ll. In a space heater of the character defined in claim 1V wherein said electrical heating unit includes a tubular core of' insulating material having an electrical resistance element Wound thereon, and wherein said means for supporting the electrical lheating unit within the inner casing comprises a pair of vertically spaced bars respectively extendng transversely of the inner casing with the opposite ends of each bar secured respectively to opposite walls of said inner casing, each of said bars being provided intermediate its length with a centrally apertured flanged' disc adapted to embrace a corresponding end of the tubular core of the heating unit with the apertures of the discs in registry with the air passage extending vertically through the heating unit.

DAVID M. TRILLING. GEORGE H'. RICH. 

